#ifndef OBSERVER_H
#define OBSERVER_H

class ISubject;
class ObserverVisitor;

class Observer {
public:
    virtual ~Observer() = default;

    virtual void accept(ObserverVisitor& visitor, ISubject* subject) = 0;

    virtual void onPlaybackStarted() = 0;
    virtual void onPlaybackStopped() = 0;

};

#endif // OBSERVER_H
